Method Geom_BSplineCurve::Segment() produces invalid B-spline curve while the source curve seems to be OK

After applying Geom_BSplineCurve::Segment(...) method to the attached curves we obtain the result curve with several close poles and knots.

Result of Steps To Reproduce scrips:

SCRIPT # 1

Draw[]> dump cc1
*********** Dump of cc1 *************
BSplineCurve
  Degree 8, 28 Poles, 5 Knots
Poles :
...
  22 : -41.6415298559676, 11.5000002955484, 113.822875195299
  23 : -41.4999999999997, 11.5000001477742, 113.822875425416
  24 : -41.4999999999996, 11.5000001477742, 113.822875425416
  25 : -41.4999999999994, 11.5000001477742, 113.822875425416
  26 : -41.4999999999992, 11.5000001477742, 113.822875425416
  27 : -41.4999999999991, 11.5000001477742, 113.822875425416
  28 : -41.4999999999989, 11.5000001477742, 113.822875425416
Knots :

   ...
   4 : 1.38173176294828 5
   5 : 1.38173176294839 9


SCRIPT # 2

Draw[]> dump cc2
*********** Dump of cc2 *************
BSplineCurve
  Degree 8, 30 Poles, 5 Knots
Poles :
...
  22 : -41.614408772683, 11.5, 113.822875655532
  23 : -41.4999999999999, 11.5, 113.822875655532
  24 : -41.4999999999999, 11.5, 113.822875655532
  25 : -41.4999999999998, 11.5, 113.822875655532
  26 : -41.4999999999997, 11.5, 113.822875655532
  27 : -41.4999999999997, 11.5, 113.822875655532
  28 : -41.4999999999996, 11.5, 113.822875655532
  29 : -41.4999999999996, 11.5, 113.822875655532
  30 : -41.4999999999995, 11.5, 113.822875655532
Knots :

   ...
   4 : 0.807999411490432 7
   5 : 0.807999411490455 9